Fabrication method of embedded chip substrate

ABSTRACT

An embedded chip substrate includes a first insulation layer, a core layer, a chip, a second insulation layer, a first circuit layer, and a second circuit layer. The core layer disposed on the first insulation layer has an opening that exposes a portion of the first insulation layer. The chip is adhered into a recess constructed by the opening and the first insulation layer. The second insulation layer is disposed on the core layer for covering the chip. The first circuit layer is disposed at the outer side of the first insulation layer located between the first circuit layer and the core layer. The second circuit layer is disposed at the outer side of the second insulation layer located between the second circuit layer and the core layer. The first circuit layer is electrically connected to the second circuit layer that is electrically connected to the chip.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/564,421, filed Aug. 1, 2012, which is a divisional application ofU.S. patent application Ser. No. 12/500,841, filed on Jul. 10, 2009, nowabandoned, which claims the priority benefit of Taiwan Application No.97127864, filed on Jul. 22, 2008. The entirety of each of theabove-mentioned patent applications is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention generally relates to a fabrication method of asubstrate. More particularly, the present invention relates to afabrication method of an embedded chip substrate.

Description of Related Art

With recent progress of electronic technologies, electronic productsthat are more user-friendly and with better functions are continuouslydeveloped. Further, these products are designed to satisfy requirementsfor lightness, slimness, shortness, and compactness. In a housing of theelectronic product, a circuit board is often disposed for carryingvarious electronic elements. The electronic elements occupy the carryingarea on the circuit board. Hence, when the number of the electronicelements increases, the carrying area on the circuit board is requiredto be extended. As such, the area occupied by the circuit board isinevitably increased as well, which deteriorates miniaturization of theelectronic products. In addition, the circuit boards used in chippackages also encounter the similar issue.

SUMMARY OF THE INVENTION

The present invention further provides a fabrication method of anembedded chip substrate. A chip in the embedded chip substrate formed byconducting said fabrication method does not occupy a carrying area of acircuit board.

In the present invention, a fabrication method of an embedded chipsubstrate is provided hereinafter. First, a core layer that has anopening is provided. Next, a first insulation layer and a firstconductive layer are provided. The first conductive layer is disposed onthe first insulation layer. The core layer is then disposed on the firstinsulation layer that is located between the core layer and the firstconductive layer. After that, a chip is adhered into a recess formed bythe opening and the first insulation layer. Thereafter, a secondinsulation layer and a second conductive layer are provided. The secondconductive layer is disposed on the second insulation layer. The secondinsulation layer is then disposed on the core layer. The secondinsulation layer is located between the core layer and the secondconductive layer and covers the recess. Afterwards, the first conductivelayer, the first insulation layer, the core layer, the second insulationlayer, and the second conductive layer are laminated. Next, the firstconductive layer and the second conductive layer are respectivelypatterned, so as to form a first circuit layer and a second circuitlayer. The first circuit layer is electrically connected to the secondcircuit layer, and the second circuit layer is electrically connected tothe chip.

In light of the foregoing, the chip is embedded into the circuit boardaccording to the present invention, and therefore the chip does notoccupy the carrying area of the circuit board.

In order to make the above and other features and advantages of thepresent invention more comprehensible, several embodiments accompaniedwith figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings constituting a part of this specification areincorporated herein to provide a further understanding of the invention.Here, the drawings illustrate embodiments of the invention and, togetherwith the description, serve to explain the principles of the invention.

FIGS. 1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K and 1L are schematiccross-sectional flowcharts illustrating a process of manufacturing anembedded chip substrate according to an embodiment of the presentinvention.

FIGS. 2A and 2B are schematic cross-sectional flowcharts illustrating aprocess of manufacturing an embedded chip substrate according to anotherembodiment of the present invention.

FIG. 3 is a schematic cross-sectional flowchart illustrating a processof manufacturing an embedded chip substrate according to still anotherembodiment of the present invention.

FIGS. 4 and 5 are schematic cross-sectional views illustrating twomodifications of the embedded chip substrate depicted in FIG. 1L.

DESCRIPTION OF EMBODIMENTS

FIGS. 1A through 1L are schematic cross-sectional flowchartsillustrating a process of manufacturing an embedded chip substrateaccording to an embodiment of the present invention. FIGS. 2A and 2B areschematic cross-sectional flowcharts illustrating a process ofmanufacturing an embedded chip substrate according to another embodimentof the present invention. FIG. 3 is a schematic cross-sectionalflowchart illustrating a process of manufacturing an embedded chipsubstrate according to still another embodiment of the presentinvention.

First, referring to FIG. 1A, a core layer 10 is provided. The core layer10 includes a core dielectric layer 12 and two conductive layers 14 thatare disposed at opposite sides of the core dielectric layer 12,respectively. The core dielectric layer 12 can be an insulation board.Additionally, in other embodiments that are not depicted in thedrawings, a multi-layered board can serve as a substitute for the coredielectric layer 12 of the present embodiment. The multi-layered boardcan be composed of multiple circuit layers and multiple insulationlayers alternately arranged.

Next, referring to FIG. 1B, the two conductive layers 14 are patterned,respectively, so as to form two core circuit layers 14 a. After that,referring to FIG. 1C, an opening 16 is formed on the core layer 10.Here, a method of forming the opening 16 includes performing a routingprocess, such as a mechanical drilling process, a punching process, orany other appropriate routing processes.

Thereafter, referring to FIG. 1D, a first insulation layer 110 and afirst conductive layer 120 are provided. The first conductive layer 120is disposed on the first insulation layer 110, and a material of thefirst insulation layer 110 is, for example, a two-state curablecompound. In the present embodiment, a resin coated copper (RCC) can beused to form the first insulation layer 110 and the first conductivelayer 120. After that, the core layer 10 is disposed on the firstinsulation layer 110, and the first insulation layer 110 is locatedbetween the core layer 10 and the first conductive layer 120. Besides,the opening 16 and the first insulation layer 110 together form a recessR.

Afterwards, referring to FIG. 1E, a chip 130 is adhered into the recessR. In the present embodiment, the chip 130 is adhered into the recess Rby disposing a bottom adhesion layer 142 on the first insulation layer110, so as to adhere the chip 130 onto the first insulation layer 110.Additionally, a side wall adhesion layer 144 is formed between the innerside wall of the recess R and the side wall of the chip 130, so as toadhere the chip 130 to the inner side wall of the recess R. Besides, inother embodiments, the chip 130 can also be adhered into the recess Ronly by means of the bottom adhesion layer 142 (as shown in FIG. 2A) orthe side wall adhesion layer 144 (as shown in FIG. 3).

A material of the bottom adhesion layer 142 is, for example, polyimide(PI), or any other appropriate adhesive materials. By contrast, amaterial of the side wall adhesion layer 144 is, for example, epoxyresin, or any other appropriate adhesive materials.

Next, referring to FIG. 1F, a second insulation layer 150 and a secondconductive layer 160 are provided. The second conductive layer 160 isdisposed on the second insulation layer 150. In the present embodiment,the RCC can be used to form the second insulation layer 150 and thesecond conductive layer 160. The second insulation layer 150 is thendisposed on the core layer 10. Here, the second insulation layer 150 islocated between the core layer 10 and the second conductive layer 160and covers the recess R.

After that, referring to FIG. 1G, the first conductive layer 120, thefirst insulation layer 110, the core layer 10, the second insulationlayer 150, and the second conductive layer 160 are laminated. Besides,the first insulation layer 110 can be heated during the lamination.Since the first insulation layer 110 can be made of the two-stagecurable compound, a portion of the first insulation layer 110 overflowsbetween the side wall of the chip 130 and the inner side wall of therecess R.

Thereby, no air or moisture would exist between the side wall of thechip 130 and the inner side wall of the recess R, such that anoccurrence of a popcorn effect can be avoided. Moreover, a material ofthe second insulation layer 150 can also include the two-stage curablecompound, which is conducive to filling up the space between the sidewall of the chip 130 and the inner side wall of the recess R.

According to other embodiments, when the chip 130 is adhered into therecess R only by means of the bottom adhesion layer 142 (as shown inFIG. 2A), the lamination of the first conductive layer 120, the firstinsulation layer 110, the core layer 10, the second insulation layer150, and the second conductive layer 160 and the heating of the firstinsulation layer 110 allow the space between the side wall of the chip130 and the inner side wall of the recess R to be filled with a portionof the first insulation layer 110 (as shown in FIG. 2B). As such, it isnot necessary to fill the space between the side wall of the chip 130and the inner side wall of the recess R with other fillers forpreventing the occurrence of the popcorn effect.

After that, referring to FIG. 1H, a plurality of conductive blind vias Bpenetrating the second insulation layer 150 are formed in the presentembodiment, so as to electrically connect the chip 130 to the secondconductive layer 160. Next, referring to FIG. 1I, the first conductivelayer 120 and the second conductive layer 160 are respectivelypatterned, so as to form a first circuit layer 122 and a second circuitlayer 162.

Referring to FIG. 1J, a plurality of conductive through holes Tpenetrating the second insulation layer 150, the core layer 10, and thefirst insulation layer 110 are then formed in the present embodiment, soas to electrically connected the first circuit layer 122 to the secondcircuit layer 162.

Thereafter, referring to FIG. 1K, in the present embodiment, a build-upstructure 170 can be further formed at the outer side of the firstinsulation layer 110 and the outer side of the second insulation layer150, respectively. A plurality of solder pads 172 are respectivelydisposed at the outer sides of the build-up structures 170. Next,referring to FIG. 1L, a solder mask layer 180 is formed on the build-upstructures 170, respectively, so as to expose the corresponding solderpads 172. To avoid the surfaces of the solder pads 172 from beingoxidized, an electrical connection layer 190 can then be formed on thesolder pads 172. Here, the electrical connection layer 190 is, forexample, a Ni/Au composite layer.

The structure of the embedded chip substrate in FIG. 1L is elaboratedhereinafter.

FIGS. 4 and 5 are schematic cross-sectional views illustrating twomodifications of the embedded chip substrate depicted in FIG. 1L.

As shown in FIG. 1L, an embedded chip substrate 200 of the presentembodiment includes a first insulation layer 110, a core layer 10, achip 130, a second insulation layer 150, a first circuit layer 122, anda second circuit layer 162. The first insulation layer 110 is made of atwo-stage curable compound, for example.

The core layer 10 is disposed on the first insulation layer 110 and hasan opening 16 that exposes a portion of the first insulation layer 110.The opening 16 and the first insulation layer 110 together form a recessR where the chip 130 is adhered. In the present embodiment, a bottomadhesion layer 142 is disposed between the chip 130 and the firstinsulation layer 110, and a side wall adhesion layer 144 is disposedbetween the inner side wall of the recess R and the side wall of thechip 130, so as to adhere the chip 130 into the recess R.

Besides, referring to FIG. 4, in other embodiments, the chip 130 can beadhered into the recess R only by means of the bottom adhesion layer142. Note that the first insulation layer 110 can be extended into thespace between the inner side wall of the recess R and the side wall ofthe chip 130, and therefore it is not necessary to fill the space withother fillers for preventing the occurrence of the popcorn effect.Moreover, the material of the second insulation layer 150 can alsoinclude the two-stage curable compound, and thus the second insulationlayer 150 can also be extended into the space between the inner sidewall of the recess R and the side wall of the chip 130 (not shown).Besides, referring to FIG. 5, in other embodiments, the chip 130 can beadhered into the recess R only by means of the side wall adhesion layer144.

As shown in FIG. 1L, the second insulation layer 150 is disposed on thecore layer 10 for covering the chip 130. In addition, the material ofthe second insulation layer 150 can include the two-stage curablecompound. The first circuit layer 122 is disposed at the outer side ofthe first insulation layer 110, and the first insulation layer 110 islocated between the first circuit layer 122 and the core layer 10. Thesecond circuit layer 162 is disposed at the outer side of the secondinsulation layer 150, and the second insulation layer 150 is locatedbetween the second circuit layer 162 and the core layer 10.

In the present embodiment, the first circuit layer 122 and the secondcircuit layer 162 can be electrically connected to each other through aplurality of conductive through holes T penetrating the secondinsulation layer 150, the core layer 10, and the first insulation layer110. The second circuit layer 162 and the chip 130 can be electricallyconnected to each other through a plurality of conductive blind vias Bpenetrating the second insulation layer 150.

Additionally, in the present embodiment, a build-up process can beperformed at the outer side of the second insulation layer 150 and theouter side of the first insulation layer 110 based on actual demands.According to the present embodiment, a build-up structure 170 is formedrespectively at the outer side of the second insulation layer 150 andthe outer side of the first insulation layer 110, and a plurality ofsolder pads 172 are formed at the outer side of each of the built-upstructures 170. Moreover, a solder mask layer 180 is formed respectivelyat the outer sides of the two build-up structures 170 in the presentembodiment, and each of the solder mask layers 180 exposes thecorresponding solder pads 172.

To avoid the surfaces of the solder pads 172 from being oxidized, anelectrical connection layer 190 can be further formed on each of thesolder pads 172. Here, the electrical connection layer 190 is, forexample, a Ni/Au composite layer.

Based on the above, the chip is embedded into the circuit boardaccording to the present invention, and therefore the chip does notoccupy the carrying area on the circuit board. Further, in the aforesaidembodiments, the first insulation layer can be made of the two-stagecurable compound. Thus, when the first conductive layer, the firstinsulation layer, the core layer, the second insulation layer, and thesecond conductive layer are laminated, the first insulation layer can beheated, such that the first insulation layer overflows between the sidewall of the chip and the inner side wall of the recess. Thereby, no airor moisture would exist between the side wall of the chip and the innerside wall of the recess, so as to prevent the occurrence of the popcorneffect.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An embedded chip substrate, comprising: adielectric layer defining an opening having an inner side wall; a firstcircuit layer disposed over the dielectric layer; a second circuit layerdisposed over the dielectric layer on a side of the dielectric layeropposite to the first circuit layer; a conductive through hole extendingfrom a top surface of the dielectric layer to a bottom surface of thedielectric layer; a first insulation layer disposed over the firstcircuit layer; a second insulation layer disposed over the secondcircuit layer; a chip having a side wall, the chip adhered in a recessformed by the opening and the second insulation layer; a plurality offirst vias in the first insulation layer; a third circuit layer disposedover the first insulation layer and electrically connected to the chipthrough the first vias; and a fourth circuit layer disposed over thesecond insulation layer, the fourth circuit layer electrically connectedto the first circuit layer through the conductive through hole; whereinthe first insulation layer extends into a space between the inner sidewall of the opening and the side wall of the chip.
 2. The embedded chipsubstrate as claimed in claim 1, further comprising: a bottom adhesionlayer disposed on the second insulation layer in the recess and locatedbetween the chip and the second insulation layer.
 3. The embedded chipsubstrate as claimed in claim 1, further comprising: a side walladhesion layer disposed between the inner side wall of the opening andthe side wall of the chip.
 4. The embedded chip substrate as claimed inclaim 1, wherein the conductive through hole further extends through thefirst insulation layer and the second insulation layer.
 5. The embeddedchip substrate as claim 1, wherein the dielectric layer is amulti-layered board.
 6. The embedded chip substrate as claim 1, whereinthe second insulation layer extends into the space between the innerside wall of the opening and the side wall of the chip.
 7. The embeddedchip substrate as claimed in claim 1, wherein a material of the firstinsulation layer comprises a two-stage curable compound in a curedstage.
 8. The embedded chip substrate as claimed in claim 1, wherein amaterial of the second insulation layer comprises a two-stage curablecompound in a cured stage.